My indoor range will allow me to use this unit ( when they get back in stock )
Now the issue is how to mount it to a pistol rest to fire the FN 5.7 over it.
I have been chatting with the makers because they are excited to have a way to fire all guns with it

It could be adapted to the FsN by using an offset rail mount like those used to hang 50 bajillion do-dads on M4's. Get one to take a light and clamp in a suitably-sized length of aluminum tubing to act as the "barrel" onto which you clamp the device.

Might take a bit of finaggling but it could be done. Or just wait for someone else to come up with an overpriced turnkey solution...that likely would still require finaggling to get it mounted correctly.

I shoot at an indoor range that will NOT allow anyone past the firing line.
Hence my interest in one of these.
We have been debating making one attached to a pistol rest that gives a solid forward position.

I know there are better chronys
and I envy you for having one
But right now, I have zip

Maybe someday I will have another outdoor range I can use,
But that day is not here ...yet.

I imagine it would change POI but anything mounted to the barrel would.\

My Graco brass catcher has been working great!
If it doesn't catch it it drops it at my feet.
Maybe a multi mount on the rail?

I wanted one of these for testing subsonics but conventional mounting has that strap around the muzzle end which doesn't work for semi-autos.
If they or someone else makes a rail mount for one, I would certainly be interested in getting it. Bit having the sensor hard mounted to the bench & having to PROPERLY line up the gun every time you shoot? I don't think you can do that without major set up/tear down. Not worth it.

Any chance they let you do something like this?
The chrono will probably need it's own light source if indoors but they make lamps & battery packs for them.
I'm not even sure how stable a platform like this might be - just an idea.

the magnetospeed does not use light
Or shadows
It reads magnetic ( or metallic ) presence of the bullets passing over the sensors on the Bayonet shaped attachment.

That is why placement from the muzzle is critical
I was thinking along the lines of your drawing.
Just in place of the "bench" would be a fixed pistol rest.
So the pistol is always the same distance from the sensors.

I understand the mangeto thing, I've looked into it on more than just their website. Some people on other forums have written up reviews on those chronos. So far they are all positive.
My "issue" is maintaining position for each shot with a semi-auto. Normally, the unit is mounted to the gun so that when one moves, they both move and thus stay aligned and in the proper position. No one that I have found, outside of the manufacture's shop, has tried a separate mount test. Even then, the manufacturer used a test stand for firing instead of an actual firearm. If you think you can maintain ideal position/alignment for each shot then go for it & I wish you the best.

I am just trying to explain why I felt, for my purposes, it wasn't worth it. I already own a chronograph so until I accidentally put a bullet through it, I can't see spending more money on something that would be a hassle to make work. The drawing I made was the idea I had for use at local the indoor range which has the same rule of no one goes beyond the line and my chrono needs a light source.

If magneto makes it easy & engineers a rail mount for it, I'm in. Until then, it's not worth it to me.

This adapter will allow the MagnetoSpeed V3 to be used on most pistols and short barreled rifles that have a Picatinny style rail. Read the dimensional restrictions to see if it fits your weapon before purchasing.

Demonstration video

*This adapter is not compatible with some proprietary manufacturers' rails, or with Glock compact or sub-compact model pistols. Does not work with CZ models P-01, P-06, and 75D.

Might go in on one of these with a few buddies in the office. This is a huge selling point for me, as I can mount it to most rifles and pistols I own and would want to chrono.

GONRA is placing all my bets on www.mylabradar.com .
Have one but need LOTTSA shootin' / testin' experience
before reporting any results to you persnickety guys.
Initial crude tests (couple years ago) were Just Fine.

panzermk2 wrote:
I can shoot the same lot of ammo through the same gun. Every thing can be identical including the shooter except for one day apart. Temp and humidity the same since I have that controlled in the shop and our indoor range.

You know what? There will be an 100 to 200 fps difference sometimes.

Also measuring at the muzzle, if you can get a reading, gives you lower velocities. The bullet is not done accelerating until well after it has left the barrel.

Also factor in the variance in equipment. A $300 dollar chrono is no where as consistent machine to machine as a $3000 chrono.

Now as to why the above difference of 200 fps or sometimes it's 20 fps?

I asked this myself and discovered the answer in one of my 100 year old ballistics manuals.

Barometric pressure. So now when we load ammo it's test lot has all the standard data including BAR written on the box. When the ammo is tested the BAR at the range is also recorded. I have started, mind you STARTED, working on the correlation in fps change and BAR. In fact when some of my 10mm was tested by that third party the velocities he got where consistently HIGHER then any I had ever gotten including with the test loads from that run of ammo his samples came from.

Now here some really good reading from the creator of my primary pressure testing system when we where discussing what a pain in the ass it is to measure 5.7x28 velocities accurately.

Understand rifle/handgun velocities listed as "Muzzle" are usually taken 10+ ft from the muzzle.
This is the industry standard and even described in SAAMI protocols. Shotgun data may
be 5 ft. and real big bores to 15 or 20 ft. The data is never actually collected at the muzzle.

Since the advent of good radar range instrumentation it has been known the bullet continues
to accelerate 8 to 12 inches after exiting the muzzle. More importantly, the bullet exits
with venting gas and does not begin to decelerate until it punches out of the gas plume as far
as 4 to 6 ft. from the muzzle.

The above shot taken in a vapor chamber clearly shows venting gas, the shock cone where air drag
starts, etc. Only when a bullet punches through the venting gas will air drag cause velocity
erosion. Those software products that attempt to back up velocity to the muzzle from
chronograph screens are bogus and entirely miss this physical phenomenon.

The bottom line is even if erosion starts at 4, 6 or 8 ft. with screens at 10 ft; the
slight error is less then the instrumentation error that can be expected from light trap
chronograph technology and certainly less then the ambient temperature affect on propellents
or normal shot to shot deviation. Since the point where velocity erosion begins can only be
learned on a radar range, the industry has adopted standard screen spacing.

The venting gas in the above shot contains allot of heat. All chronograph sensors read into the
IR spectrum so the hot gasses only serve to blind the first sensor.

GONRA is placing all my bets on www.mylabradar.com .
Have one but need LOTTSA shootin' / testin' experience
before reporting any results to you persnickety guys.
Initial crude tests (couple years ago) were Just Fine.

I think Buffman was playing with one of those and pretty much hated it.

Pretty much impossible for a correction to really work since they would have to know the bullet weight, BC and the speed it's supposed to be going in the first place to adjust the off set. This is why I called BS on that thing the first time I saw it. I have spent to much time dealing with Chrono's and their failings over the last 15 plus years. I have a rant thread about it.

Pro Chrono 2. Best damn chrono money can buy and it's cheap. Circuit board my die in a few years depending on how many rounds you shoot over it but it does NOT matter since they are so cheap. Plus their software interface is the best also.